feat(main): 添加并发计算和订单分发功能

- 新增 operations1.go 文件实现带通道的并发价格计算
- 新增 orderdispatch.go 文件实现订单分发和客户通知- 修改 main.go 调用新的并发计算和订单分发函数
- 更新 product.go 中 "Unsteady Chair"价格从 29.95 到 75
- 修正 product.go 中产品组初始化逻辑，确保正确添加新产品组- 在 CalcStoreTotal 函数中增加执行开始提示信息- 在 TotalPrice 方法中增加产品名称打印信息
- main 函数中调整执行顺序并增加换行符以改善输出格式

14-concurrency/concurrency/main.go

@@ -1,9 +1,14 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+)
 
 func main() {
 	fmt.Println("main function started")
 	CalcStoreTotal(Products)
-	fmt.Println("main function complete")
+	CalcStoreTotal1(Products)
+	main1()
+	main2()
+	fmt.Println("\nmain function complete")
 }

14-concurrency/concurrency/operations.go

@@ -3,6 +3,7 @@ package main
 import "fmt"
 
 func CalcStoreTotal(data ProductData) {
+	fmt.Println("\nCalcStoreTotal function started:")
 	var storeTotal float64
 	for category, group := range data {
 		storeTotal += group.TotalPrice(category)
@@ -12,6 +13,7 @@ func CalcStoreTotal(data ProductData) {
 
 func (group ProductGroup) TotalPrice(category string) (total float64) {
 	for _, p := range group {
+		fmt.Println(category, "product:", p.Name)
 		total += p.Price
 	}
 	fmt.Println(category, "subtotal: ", ToCurrency(total))

14-concurrency/concurrency/operations1.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func CalcStoreTotal1(data ProductData) {
+	fmt.Println("\nCalcStoreTotal1 function started:")
+	var storeTotal float64
+	var channel chan float64 = make(chan float64, 2)
+	for category, group := range data {
+		go group.TotalPrice1(category, channel)
+	}
+	for i := 0; i < len(data); i++ {
+		fmt.Println("-- channel read pending", len(channel), "items in buffer,size", cap(channel))
+		value := <-channel
+		fmt.Println("-- channel read complete", value)
+		storeTotal += value
+		time.Sleep(time.Second)
+	}
+	fmt.Println("Total: ", ToCurrency(storeTotal))
+}
+
+func (group ProductGroup) TotalPrice1(category string, resultChannel chan float64) {
+	var total float64
+	for _, p := range group {
+		// fmt.Println(category, "product:", p.Name)
+		total += p.Price
+		time.Sleep(time.Millisecond * 100)
+	}
+	fmt.Println(category, "channel sending: ", ToCurrency(total))
+	resultChannel <- total
+	fmt.Println(category, "channel send complete")
+	return
+}

14-concurrency/concurrency/orderdispatch.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+type DispatchNotification struct {
+	Customer string
+	*Product
+	Quantity int
+}
+
+var Customers = []string{"Alice", "Bob", "Charlie", "David", "Edith", "Fred"}
+
+func DispatchOrders(channel chan<- DispatchNotification) {
+	rand.Seed(time.Now().UTC().UnixNano())
+	orderCount := rand.Intn(3) + 2
+	fmt.Println("Order count:", orderCount)
+	for i := 0; i < orderCount; i++ {
+		channel <- DispatchNotification{
+			Customer: Customers[rand.Intn(len(Customers))],
+			Quantity: rand.Intn(5) + 1,
+			Product:  ProductList[rand.Intn(len(ProductList))],
+		}
+		//if i == 1 {
+		//	notification := <-channel
+		//	fmt.Println("Read:", notification.Customer)
+		//}
+	}
+
+	close(channel)
+}
+
+func main1() {
+	fmt.Println("\nmain1")
+	dispatchChannel := make(chan DispatchNotification, 100)
+	go DispatchOrders(dispatchChannel)
+	for {
+		if details, open := <-dispatchChannel; open {
+			fmt.Println("Dispatching order to", details.Customer, ":", details.Product.Name, "x", details.Quantity)
+		} else {
+			fmt.Println("Channel has been closed")
+			break
+		}
+	}
+}
+
+func main2() {
+	fmt.Println("\nmain2")
+	dispatchChannel := make(chan DispatchNotification, 100)
+	go DispatchOrders(dispatchChannel)
+	for details := range dispatchChannel {
+		fmt.Println("Dispatching order to", details.Customer, ":", details.Product.Name, "x", details.Quantity)
+	}
+	fmt.Println("Channel has been closed")
+}

14-concurrency/concurrency/product.go

@@ -16,7 +16,7 @@ var ProductList = []*Product{
 	{"Corner Flags", "Soccer", 34.95},
 	{"Stadium", "Soccer", 79500},
 	{"Thinking Cap", "Chess", 16},
-	{"Unsteady Chair", "Chess", 29.95},
+	{"Unsteady Chair", "Chess", 75},
 	{"Bling-Bling King", "Chess", 1200},
 }
 
@@ -33,7 +33,7 @@ func init() {
 		if _, ok := Products[product.category]; ok {
 			Products[product.category] = append(Products[product.category], product)
 		} else {
-			Products[product.category] = ProductGroup{}
+			Products[product.category] = ProductGroup{product}
 		}
 	}
 }